CABI has published a new book which explores the ecology and management of invasive Prosopis juliflora trees which have severely impacted landscapes and the livelihoods of pastoral communities in Eastern Africa.

The 272-page book, entitled ‘The Ecology and Management of Invasive Prosopis Trees in Eastern Africa,’ follows 10 years of extensive research conducted by CABI and partners under the Woody Weeds and Woody Weeds + projects.

The new CABI book is aimed at academics and students in the field of ecology, scientific managers of natural ecosystems, policymakers and regulators in and around Eastern Africa that may be affected by Prosopis juliflora.

It is edited by CABI’s Dr Urs Schaffner, Prof Brian van Wilgen of Stellenboch University, South Africa, Dr Albert Ehrensperger from the University of Bern, Switzerland, and Dr Ketema Bekele of Haramaya University, Ethiopia.

Negative impacts on biodiversity and ecosystem services

In eastern Africa, Prosopis juliflora, popularly known in Kenya as Mathenge and in Tanzania as Mrasha, invades rangeland, cropland, settlements and riparian ecosystems, causing negative impacts on biodiversity and ecosystem services that rural communities depend on.

Prosopis juliflora has even contributed to the deaths of Lesser Flamingos in recent years. This led to CABI scientists joining partners at Lake Bogoria National Reserve in Kenya to remove the invasive weed from the lake’s shoreline.

‘The Ecology and Management of Invasive Prosopis Trees in Eastern Africa’ synthesises information on an important environmental problem - the invasion of natural ecosystems in Africa by alien Prosopis trees, and how they should be managed.

It addresses how the problem came about, what we know about how it works, and how it can potentially be managed at different scales.

Dr Urs Schaffner, Head of Ecosystems Management at CABI and a co-editor of the book, said, “The book has a focus on eastern Africa but includes studies from elsewhere. Prosopis trees were originally introduced to Africa as early as 1880 (in South Africa), and later to eastern Africa in 1917 (in Sudan).

“They are difficult to manage due to their ecological features, such as their ability to produce copious amounts of seed, and to compete successfully with native species for resources, but also because they have both beneficial uses and negative impacts, making them conflict species, where people disagree on goals for management and how they should be achieved.”

Dr Schaffner said that while the Woody Weeds project was implemented in Kenya, Ethiopia and Tanzania, the Woody Weeds+ project focused on Kenya. In Tanzania, CABI co-led a project with Tanzanian partners in the Lake Natron Basin in northern Tanzania which supported the implementation of the new Tanzanian National Invasive Species Strategy and Action Plan, focusing on Prosopis juliflora.

The Woody Weeds + Project is funded by Swiss Agency for Development and Cooperation (SDC). It is a collaborative effort that includes several partners such as the Centre for Training and integrated Research in ASAL Development (CETRAD), KEFRI, University of Nairobi, Centre for Development and Environment (CDE) at University of Bern, Farmbetter, and various community based organisations and natural resource management organisations.